This invention relates to novel quaternary nitrogen-containing phosphonate compounds, including bisphosphonates, phosphonoalkylphosphinates, phosphonocarboxylates, and phosphonosulfonates, preferably bisphosphonates and phosphonoalkylphosphinates. This invention also relates to pharmaceutical compositions containing these novel compounds as well as to a method of treating or preventing certain metabolic bone disorders characterized by abnormal calcium and phosphate metabolism by utilizing a compound or pharmaceutical composition of the present invention. Specifically, this invention relates to a method of treating or preventing osteoporosis and arthritis, especially rheumatoid arthritis and osteoarthritis by utilizing a compound or pharmaceutical composition of the present invention. This invention also relates to pharmaceutical compositions containing these novel compounds as well as to a method of treating or preventing dental calculus, plaque, and gingivitis. Specifically, this invention also relates to a method of treating or preventing dental calculus and plaque by utilizing a compound or pharmaceutical composition of the present invention.